2D cutting

Table of costs per metre of cut

The attached tables provide a look at the costs for 1 meter of cut for the individual performances of fiber sources. In order to prepare this data, it was necessary to count on the maximum available speed for a running meter of cut, i.e. without the effect of the acceleration parameters for the given type of machine. The price of the cut in this calculation consists of two basic parameters – electrical energy costs and consumed industrial gas costs.

Energy costs

The price of electrical energy is calculated from the average price per 1 kWh in the Czech Republic, the power consumption of the machine, and the time needed for cutting one meter of length.

Gas costs

The price of industrial gases normally used consists of 80-90% of the cost of the cut and therefore the cost of obtaining it is very important. Industrial gases can be obtained in three basic ways – in individual pressure cylinders, from a manifold, or as a liquefied gas, which comes in either a Eurocell tank sized like a normal palette or is pumped into a stationary tank at the customer site. The price of gas can vary widely because of the method of delivery and therefore the costs given here are for all 3 options. Liquefied gas always offers the lowest price, but is practical for customers only in the event of using their machine for most days of the year. This is because if the gas is not used from the tank, the safety electronics undertake to clean the valve about once a day and purge the gas part of it. In the event the machine is not used too frequently, costs can go up due to the gas losses that occur.

The gas costs used in the calculation are set according to the prices which we are currently able to guarantee customers in conjunction with our business partner LINDE. They are significantly lower than the prices in the official price list for this vendor. It should still be noted that, according to the information from our customers, noticeably lower prices can be obtained.

Laser consumables

The costs for consumables are not included in the calculation. We took this step in order to simplify the entire calculation and mainly because it will have minimum effect if included in the final amount.

For the proper use of a fiber laser, consumables consist of only two items – the nozzle and protective glass laser head. When correctly used, the nozzle can provide up to 1000 working hours before changing and our ordinary price for it is around 1,000 CZK without VAT. The protective glass laser requires cleaning because otherwise impurities can lead to local overheating by the transmission beam, resulting in clouding or cracks. We therefore recommend it be regularly cleaned at the beginning of the shift with isopropyl alcohol.  When properly clean, its service life is almost unlimited – up to 3000 hours. Its current price is 2,690 CZK without VAT.

In the calculation of costs, the nozzle and glass thus account for 2 CZK per hour of machine running time. For this reason, we did not consider it necessary to include these costs in the calculation.

Other costs not included

Also not included in the costs are the costs directly related to the cutting activity, i.e. staff costs, material or amortization of the machine.

Economic analysis of operation

In the event of interest, we will be happy to prepare a complete economic analysis of operating the machine. In order to create such an analysis, we require additional information from the customer, especially:

• Drawing of the type of product to form the basis of the analysis.
• Exact type of machine the customer is interested in
• Type of material to be used in production

The economic analysis of operation will be able to include in the calculation of the machine the parameter called production efficiency. This parameter specifies the percentage of time when the laser is effectively cutting and the time when the material is being replaced, the head is crossing over, or other delays. The cutting speed here does not include tabular continuous speed, but in accordance with the complexity of the sample piece, the speed is adjusted according to the effect of the acceleration of the machine. In layman’s terms, this parameter specifies the extension of cutting time due to decreasing and subsequently restoring the speed of the cut during pass-through across a sharp angle in the drawing.

We can use the economic analysis to answer several questions:

• How many pieces of the standardized product we are able to cut for a period of time (Shift, month, year…)?
• Or – what type of machine do we need in order to produce the required quantity per unit of time?
• If in current cooperation we pay xx CZK per cut, how long will it be before we get a return on our investment in the machine?
• What power source and equipment for the machine are best for our production?

In the event you are interested in an analysis of laser operation in your company, feel free to contact us. We will try to prepare it in cooperation with you in the shortest possible time.

Other options for reducing costs per cut

We have listed in the table the costs per cut with a recommended type of industrial gas for the given type of material. From practice, however, it is necessary to add that for lower demands on the quality of the cut edge, it is possible to make cuts on some material using, for example, compressed air. The cutting time will be longer, the cut edge courser, but, for example, more than sufficient for subsequent welding. For using air, however, it is necessary to ensure that the compressed air will have not only enough pressure, but will also be completely free of oil and mechanical impurities. Oil residues in pressurized air can easily start to react with oxygen in the pressure line and so cause a fire.

Another option for reducing costs per cut is the offer of stainless steel, which, for preserving the maximum quality of the cut edge, is ordinarily cut using industrial nitrogen. Nitrogen cools around the cut and primarily prevents exothermic reactions, thanks to which the cut edge preserves its smoothness and the color of the material itself. When cutting with oxygen, the edge will be coarser and dark, similarly as when cutting with air, but using oxygen makes it possible to significantly increase cutting speed and the maximum strength of the material which the given machine is able to do.

Calculation of costs per 1 m of cut

Cutting speed of HSG fiber lasers